Boosting the Electrochemical Performance of a Spinel Cathode with the In Situ Transformed Allogenic Li-Rich Layered Phase

High-voltage spinel materials have attracted widespread attention because of their advantages such as good rate performance, low cost, abundant source, and easy preparation. However, the Mn dissolution and Jahn–Teller effect of spinel materials during cycling limit their practical application. In this paper, the allogenic composites (1 – x)­Li­(Ni0.2Co0.1Mn0.7)2 O4·xLi1.2(Ni0.2Co0.1Mn0.7)0.8O2 (x = 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5) are developed by the carbonate co-precipitation method combined with the high-temperature sintering method, which are certified by the X-ray diffraction (XRD) spectrum and transmission electron microscopy (TEM) image. The results show that the lithium-rich phase of the allogenic composites can effectively improve the initial discharge capacity, alleviate the side reaction between the spinel material and the electrolyte, and improve the cycle stability. This work reveals the relationship between the structure and electrochemical performance of the in situ transformed spinel@Li-rich allogenic composites and provide a new clue to design a high-performance spinel cathode for advanced Li-ion batteries.